Not applicable.
(1) Field of the Invention
The invention relates to acoustic sensors for underwater monitoring and is directed more particularly to an acoustic vector sensor.
(2) Description of the Prior Art
It is known to use pressure-sensing hydrogphones in submarine sonar systems. However, it is desirable to improve the sensitivity of sonar systems, while at the same time reducing self noise generated by the platform on which the sensors are mounted. By improvement of sensitivity to target noise and reduction of sensitivity to self-noise, improvements in target bearing and elevation are realized with consequent improvements in target angle and speed estimations.
An object of the invention is, accordingly, to provide a vector sensor for detecting and monitoring underwater targets, which sensors are more sensitive to target acoustics than hydrophones and less sensitive to self-noise.
With the above and other objects in view, as will hereinafter appear, a feature of the present invention is the provision of an acoustic vector sensor for monitoring acoustic energy underwater, the sensor comprising an acoustics sensing tri-axial accelerometer, a body of syntactic foam encasing the accelerometer, a body of viscoelastic rubber encasing the body of syntactic foam, and a rigid plastics coating encasing the body of viscoelastic rubber.
The above and other features of the invention, including various novel details of construction and combinations of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular device embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principles and features of this invention may be employed in various and numerous embodiments without departing from the scope of the invention.